Performance Evaluation of a Novel Sample In-Answer Out (SIAO) System Based on Magnetic Nanoparticles

In recent years, the prevention, control, diagnosis and treatment of infectious diseases has become a global focus for public health. Traditional methods for pathogen testing have some major disadvantages including the need for highly skilled staff and expensive instrumentation, while procedural aspects are complex and sensitive to the environment. These shortcomings have greatly limited the application of traditional testing in on site pathogen detection. In this paper, we present a new point-of-care-testing (POCT) system based on magnetic nanoparticles that enable sample in-answer out (SIAO) automated real-time testing for pathogens. Various performance tests were conducted on the instrument. Nucleic acid extraction efficiencies of SIAO versus manual systems were 95.49% and 84.33%, respectively. Real-time PCR by two methods (TaqMan-based probe and SYBR green dye) in the SIAO system was achievable, with comparable results to the manual method. Nucleic acid testing with the SIAO system was repeatable and better than with manual testing. The SIAO system had good anti-pollution performance with easy avoidance of inter-assay cross contamination. Finally, use of the SIAO system for adenovirus detection produced similar results to LightCycler2.0 system assay findings. The amplification plots and Ct values suggested similar amplification plots shapes for adenovirus testing with the SIAO system and with real-time fluorescence PCR testing and commercial instrument post-manual nucleic acid extraction. Collectively, these findings indicate that testing with the SIAO system is virtually equivalent to that of manual extraction with commercial system testing.